Liquid-flow time switch



1927' w. R. WALKER LIQUID FLOW TIME SWITCH Filed June 26, 1924 INVENTOR Patented Aug. 9, 1927.

UNITED STATES PATENT OFFICE.

WARREN R. WALKER, OF NEW DORP, NEW YORK, ASSIGNOR TO COOPER HEWITT ELEC- TRIO COMPANY, OF HOBUKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

mourn-now. TIM-E swrrcn.

Applicationfiled June 26,

My present invention relates to electric switches of the liquid flow type and particularly to such a switch in which there is a time lag in the circuit making motion.

For injecting a time lag in liquid flow type switches it has heretofore been general practice to employ either a baflie of insulating material with a small liquid passage formed therethrough or a restricted tube of insulating material for the flow of the liquid from one positionof the switch to another but these forms involve difficulties rising from a lack of a positive and definite make or break between the electrode terminals of the switch in time relation to said liquid and said bafiie.

I have discovered that by positioning one of the electrodes in such a switch close to or at the bafiie thereof that-the timing of the making or breaking of the circuitis more accurately accomplished and more easily adjusted. v

I have also discovered that by making the bafile of such a switch separate from the wall of the switch container but suitably supported in close proximity thereto and having when necessary a restricted opening thereln that the construction of the switchis considerably simplified.

In some switches embodying my invention I therefore make the timing baflie of conducting material and support it by means of a lead-1n wire supported by-the wall of the switch container. In other forms I make the bafiie of insulating materialsuch as glass separate from the switch container but supported by one of the lead terminals of the switch which terminal has a portion exposed to connection with the switch liquid at said 40 baflie. In still other forms I make the bafile support and the lead separate but the electrode close to the bafile in which case the bafile may be either of insulating or conducting material.

'45 For preventing the establishment of electrical connection in the switch immediately upon movements into the circuit making position, I provide the switch of my invent on comprising a main inclo'sure or envelope with an auxiliary chamber or cup whlch opens into the main envelope at a point below equilibrium level of the mercury therein in the closed circuit position but above intermediate levels. mum quan y t m rcury n the switch I To allow the use of mini- 1924. Serial No. 722,427.

provide an extension from the other electrode thereof into proximity to said first mentioned electrode but outside said auxil iary chamber. This allows of asimple construction in which the bafile and said extension are made of a'unitary piece of metal type in which the baflie is separate from the switch wall.

It is another object of my invention to provide such a switch in which said bafile or a part thereof serves as one of the electrodes of the switch.

I employ the switch of my invention for automatically opening and closing the circuit of a load such as an advertising sign which is intermittently cut off and turned on at definite intervals for predetermined periods of time. Such a circuit and various embodiments of my invention are shown in the drawings in which:

Fig. 1, is an elevation view of an embodiment of the switch-of my invention embodying a metal bafile with electrode extension thereon and a reentrant tube within which terminates another electrode of the switch and which terminates just suificiently below in equilibrium level in the circuit making position to insure proper conductance of current through the switch. In this view the switch is shown in the circuit making oisiition with the mercury flowing past the Fig. 2, is a view similar to that of Fig. 1 with the mercury of the switch having attained equilibrium therein.

Fig. is a perspective view of the baflle of my invention with the baflle extension and the supporting lead therein.

.Fi 4 is a vertical sectional switcli of Fig. 1 along .line 44 thereof showing an end view of the bafiie of my invention.

In the drawing the tubular envelope 1 view of the has mounted therein the metal baflle 2 by i one end thereof. Said baflie is substantially means ofthe support lead 3 sealed through a semi-circular disk positioned at right angles to the envelope tube in the lower part thereof with its curved contour in close roximity to the side of said tube. At the bottom of said baflie 2 is formed the inverted V notch 5 of a restricted area which allows passage of mercury therethrough. 'On said bafile 2 and extending longitudinally from the bottom thereof is formed the extension 44 which terminates within the body of mercury 9 of the switch in the closed circuit equilibrium position thereof. At the opposite end of said envelope 1 and at its bottom is formed the depression 7 through the bottom of which is sealed the electrode 6 which terminates below the surface of the mercury in the closed circuit equilibrium position thereof. Onto said de ression 7 is formed the reentrant tube'8 WlllCll extends upwardly and terminates at a distance above the upper end of said, electrode 6 and below the mercury in the closed circuit equilibrium position. thereof. Said tube 8 forms with depression 7 an auxiliary chamber connecting withsaid main envelope through one opening which is'at the top terminus of said tube 8. Support lead 3 is fixed to said baflie 2 in a manner to secure good electric conductance therebetween as by welding or brazing, and as shown in the drawings, for example, said extension 4 is made unitarily with said baflle 2 so that said extension baflie and lead form a continuous conductor from the mercury to the exterior of the switch when the switc is in the circuit making position for example as that shown in Fig. I

In the operation of the switch of my invention to establish a circuit therethrough with a time lag therein the switch is moved from a position in which the mercury 9 thereof is between the baflie 2 and the end of the envelope through which said electrode 3 is sealed into position as denoted by" Fig. 1 in which the mercury will flow from the o ning 5 at a retarded rate and will accumu ate at the lower end of the switch where its level will rise during a definite period oftime until it passes above the edge of said tube 8 whereby said main body 9 of mercury merges with the body 9 trapped in said auxiliary chamber 7, 8 and connection is established between said electrodes 3 and 6 through said baflle 2, extension 4 and mercu 9.

- The tubular shaped member 8, it is to be lar member 8 ifthe thermal co-eflicient ex pansion thereof permits of such 'uncture or a series of rings of suitable g asses may be interposed between the glass ring and the -quartz, borosilicate able gas or mixture of chamber, over said dividin greater co-eflicient of expansion than that of glass and less than eat of the container material, to withstand the ravages of high temperatures in service; or the tube 8 may be provided at its to with a cap piece of ass, or other material capableof withstanding the effects of high temperatures at the pointof the break be tweenthe mercury pool, and, by the use of either construction, the effects of high temperatures and rapid temperature fluctuations are not transmitted to the container material of the switch. I

It is of course to be understood that when desired a proper atmosphere as of hydrogen, nitrogen, carbon dioxide, or an suitases is provlded in the switch envelope to aldin the dissipation of the heat of I claim: 1. In a liquid flow time switch compris- 'ing a sealed envelope, a main chamber and a sub-chamber divided by a member terminatin above the lower limits of said main cham r, mercury in said envelope suflicient to extend in said main-chamber and submember in a closed circuit position of t e switch, electrodes sealed into said main chamber and said sub-chamber, and a flow restricting baffle across said main chamber in the path of mercury flow therein from an open circuit position to said closed position of the switch. 2. In a liquid flow time switch a sealed envelope comprisinga main chamber and a sub-chamber divided by a member extending above the lower limits of said main chamber, mercury in said envelope sufiicient to extend in said main-chamber and subchamber over said dividing member in a closed circuit position of the switch, electrodes sealed intosaid main chamber and said sub-chamber, and a flow restricting baffie across said main chamber in the path of mercury flowtherein from an open circuit position to said closed position of the switch, one of said electrodes extending to and beyond said baflie in said main chamber.

3. In a liquid flow time switch comprising a sealed envelope, a main chamber and a sub-chamber divided by a tubular member terminating) above the lower limits of said main cham ficient to extend in-said main-chamber and sub-chamber over said dividing member in a closed circuit position of the switch, electrodes sealed into said main chamber and said sub-chamber, and a flow restricting baffle across said main chamber in the path of mercury flow therein from an open circuit position to said closed sition of the switch, one of said electr es extending to the are, quenching 'etc.

er, mercury in said envelope suf-- and beyond said bafile in said main chamber.

4."In a liquid flow time switch" comprisin a sealed envelope, a main chamber and a su -chamber divided by a member extending above the .lower limits of said main chamber, mercury in said envelope suflicient' to extend in said main-chamber and subchamber over said dividing member in a closed circuit position of the switch, an electrode sealed into said sub-chamber, a flow restricting bafiie of conductive material across said main chamber in the path of mercury flow therein from an open circuit position to said closed position of the switch, a conducting support electrically connected to said bafiie sealed through said envelope and a conductive member on said baflie in elec- 'trical connection therewith, and extending I into said body of mercury in said closed ciring'above the lower limits of said mainchamber, mercur in said envelope sufiicient A to extend in said main-chamber and subchamber over said dividing member in a closed circuit pos1t1on of the switch, an electrode sealed into said sub-chamber, a flow open circuit position to said closed, position restricting baflie across said main chamber in the path of mercury 'flow therein from an the switch, a conducting support mounted on said bafile and sealed throu h said en- 'velope, and a member. oi conductive material carried bysaid support and extending into the mercury'in said closed circuit .position of the switch.

.Q 6. In a liquid flow time switch comprising a sealed envelo e, a main chamber, and a sub-chamber divided by a member terminatingjabove the lower limits of" said mainchamber, mercury in said envelope sufiicient "to extend in said main-chamber and sub-- chamber over said dividing member in a closed circuit 'POSltiOll of the switch, an electrode sealed into said sub-chamber, a flow restricting bafiie of conductive material across said main-chamber in the path of 'mercury flow therein from 'an open circuit position to said closed position of the switch and in electrical contact with said mercury in said closed circuit position of the switch,

chamber, a sub-chamber connectin and a lead "support for said bafli'e of conductive material having electrical connect on thereinto and sealedflthrough said envelope.

7. In a liquid flow time switch adapted to a make a quick break of a circuit and a timed make, a sealed envelope having a main chamber, a sub-chamber connectin with said main chamber at a point above t e ,bottom of the main chamber, an electrode sealed into said envelope and terminating in said sub-chamber, a contacting liquid in said container, a flow restricting baflle across the interior of said container in the line of flow of, the liquid of the switch to and from said electrode, and a second electrode sealed into said envelope and terminating in the main body thereof.

8. In a li uid flow time switch adapted to make a quicli break of a circuit and a timed make, a sealed envelope having a main with said main chamber at a point above t e bottom of the main chamber, an electrode sealed into said envelope and terminating in said sub-chamber, a contacting liquid in said container, a bafiie across the interior of said container in the line of flow of the liquid of the switch to and from said electrode, said bafile having a flow restricting passage for said mercury, and a second electrode sealed into saidenvelope and terminating in the main body thereof.

9. In a liquid flow time switch adapted to make a quick break of a circuit and a timed make, a sealed envelope having a main chamber, a sub-chamber connecting with said main chamber at a point above the bottom of the main chamber, an electrode sealed into said envelope and terminating in said sub-chamber, a contacting liquid in said container, abafiie across the lnterior of said container in the line of flow of the liquid of the switch to and vfrom said electrode, said bafile having a flow restricting passage for said mercury and being positioned with respect to said wall to provide a space therebetween substantially greater than the volume of mercury therebetween in the closed circuit position of the switch, and a second electrode sealed into said envelope and terminating in the main .bod thereof.

' Signed at Ho oken in the county of Hudson and State of New Jerseythis 24th day of June, A. D. 1924. I Y WARREN R. WALKER. 

